In the manufacturing of an IC (Integrated Circuit), various layers are formed on a surface of a thin semiconductor wafer shaped like a disk (hereinafter may be called an “initial wafer”) and a formed film is partially etched to form a number of circuit patterns on the semiconductor wafer (hereinafter may be called a “wafer” (or may be called a semiconductor substrate)).
In this manufacturing process of a semiconductor device, when a semiconductor wafer is found defective in the step of forming any one of the layers or in the etching step of removing a part of the layers, the semiconductor wafer is not transported to the subsequent manufacturing process and is discarded as a defective semiconductor wafer (hereinafter, may be called a “wafer being processed”).
The defective wafer being processed is discarded but the semiconductor wafer itself is not defective except for the layers formed on the surface. Thus by removing the layers formed in the manufacturing process of a semiconductor and smoothing the surface condition of the semiconductor wafer, the semiconductor wafer can be reclaimed to be identical to an initial wafer (hereinafter may be called a “reclaimed wafer”).
A reclamation method of a semiconductor wafer according to the prior art is described in, for example, Japanese Patent Laid-Open No. 2001-358107. The disclosed wafer reclamation method includes: (a) surface grinding for physically (mechanically) removing layers formed on a surface of the semiconductor wafer, (b) wet chemical etching (wet etching) for removing impurities and damage on the surface of the semiconductor wafer, (c) polishing on the edge of the semiconductor wafer, and (d) polishing (buffing and so on) for flattening the front side and/or the back side of the semiconductor wafer (for example, see Japanese Patent Laid-Open No. 2001-358107).